Safety exploder



Apr. 3, 1923. L'm H. MCEWAN SAFETY EXPLODER Filed Aug. 24, 1921 WITNESSES IN VEN 70H A TTOHNEYS Patented pr. 3, 1923.

Unirse STATES PATENT OFFICE.

HUGH MOEWAN, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR T WILLIAM W. NICOLL,

0F NEW YORK, N. Y.

SAFETY EXPLODER.

Application led August 24, 1921.* Serial No. 494,923.

T 0 alt whom it may concern,

Be it known that, I, HUGH MCEWAN, a citizen of the United States, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new and Improved Safety Exploder, of

yao

which the following is a full, clear, and

exact description. l

This invention relates. to improvements in safety exploders, an object of the invention being to provide van eXploder which will operate to detonate a cap of fulminate composition, such as co-mmonly employed in blasting caps and which is adapted for use in connection with any ordinary form or size of cap.

A further object is to provide a safety exploder of the character described which is made and transported entirely independent of any cap or exploding fulminate and which is ready for operation at the point of blast after a cap is properly' inserted therein and the exploder and cap p-roperly located with relation to blasting and tamping material.

A further object is to provide a safety exploder which will take the place 'of the ordinary fuse, which will reduce danger of accidents to a minimum, which will econo- Figure 1 is a view in longitudinal section illustrating my' improved safety exploder with the firing pin in set position.

Figure 2 is a similar view showing the firing p-in in firing position.

Figure 3 is an end view of the safety exploder with the cover in open position.

Figure 4 is a fragmentary view showing .the wire for controlling the operation of the firing pin.

My improved safety exploder consists of a cylindrical tube. 1 having at one end an annular Iiange or' head 2. This flange `or head 2 is providedwith a cover 3 having a hinged connection at one side to the head 2,

as shown at 4, and adapted to be removably It is, of course, obvious that I might employ various means for coupling the cover and the head, but I have illustrated a simple form of snap catch or fastening means which comprises a curved tongue 4 on the cover 3, which is adapted to be forced through a slot 5 on the head 2, and by reason of the curvature of the tongue, will snap into closed position and remain in such position unless forced to open position.

Within the tube 1 I provide a firing pin 6, said pin having a relatively long needlepointed end 7 adapted 'to be projected into a. cap 16 illustrated by dot and dash lines in Figures 1 and 2, when said'cap isin proper position in the end of tube 1 and the firing p1n is operated. I believe this relatively long needle-pointed firing pin will give sup erior results to any other shape of firing pin.

The firing pin 6 is made with an annular enlargement 8 at a point between its ends and adjacent the inner or rear end of the firing pin 6 I provide a longitudinalslot 9 for the reception of a controlling wire 10. This'V controlling wire 10 at its firing pin engaging end is preferably bent at a substantial right angle as shown in Figure 4, forining a finger 11, which constitutes a safety catch, which is projected through the slot 9 and is made wlth an offset portion 12 1ocated directly in the slot 9 and providing shoulders or cam faces 13 which offer resistance to the removal of the wire so' as to require a considerable pull to remove the wire, and hence, prevent possibility of accidental removal of the wire which would be dangerous. Between the enlargement 8 and the finger portion 1'1 of wire 10 a coiled spring 14 is located around the firing pin 6 and 1s under compression, but cannot act by reason of its confinement between said annular enlargement and the linger. The wire 10 passes through an opening 15 in cover 3 and is of a length suliicient to allow the wire to be carried through the tamping or embedding material after the exploder is properly set in connection with the cap A and explosive material, so that a cord or other suitable flexible device ma be connected to the free end of the wire and extend from' any desired distance from the point of explosion, so that the wire can be pulled out of the firing .pinby any one located any desired distance from thepoint of explosion.

Normally, the wire 10 will hold 4the firing pin 6 against the cover 3, as shown in-Figure 1, so that a cap indicated at 16 by dot and dash lines, can be inserted in the free end of the tube 1, and after the exploder and ca p are properly embedded in explosive material, the device is ready for operation.

The operation is as follows: When a sufcient pull, preferably four vpounds at least, 1s had on the wire 10 to draw the safety catch 11 of said wire out of the slot 9 of the firing pin 6, the spring 14 is free to expand andas it expands one end ofthe coiled spring 14'will engagel the cover 3, the

` latter acting as an abutment for the spring `the cap to insure and at the'same time the spring will force (at about one and one half pounds pressure) the firing pin into the cap, as indi- -scated clearly in Figure 2. This operation of'exploding is instantaneous with the withdrawal of the wire and the action 'is positive and explosion is assured because of the relatively long length of sharp needle point 7 which penetrates the cap or fulminate of the explosionl irrespective of the size of charge or length of cap.

llt willv be noted that with my improved safety exploder, the device factory, .as shown in Figure 1, Yand can be safely shipped to any point as no explosive is employed until the device is at vits point of use, and furthermore, itA will be noted.

that by `reason of the offset portion 12 of the safety catch 11, danger of accidental removal of the wire isv reduced toa minimum, as the wire cannot be removed eX- cept by a very appreciable pull much greater in fact than the wirecould possibly be subt jected to lby any Iaccidental contact'and, furthis safety connection Vbetween 'the thermore,

wire and the ring ,pin prevents possibility is set at the of accidental explosion during the placing' result in reducing accidents to a minimum and insurin a perfect blasting operation.

Various s i ht changesfmight be made in the general orm and arrangement of the parts described without departing from the invention, .and hence I do not limit myself to the precise details set forth, but consider myself at libery to make such changes and alterations as 'v airly fall within the spirit and scope of the appended claims.

I claim:

1. An eXploder of the character described, comprising a cylindrical tube, a head on one end of the' tube, a 'cover hingedly connected to the head and adapted to be remov ably connected to the head so as to` hold the cover aga-inst the head, a firing pin in the tube, a shoulder on the firing pin, said firing pin havmg an openlng therein, a wire projected through the cover and through the opening in the firing pin, spring under compression on thepin interposed between the wire and the shoulder.

2. An eXploder of the character described, comprising a cylindrical tube adapted to receive a cap in oneend thereof, an annular head on one end of the tube, a cover hinged to the head, said headhaving a slot therein, a spring tongue on said cover adapted to' be projected through said slot and elastically holding the cover and head t'ogether, a firing pin in the tube having a relatively long sharp needle-pointed end, a shoulder on the firing pin, said firing pin having a slot therein, said cover having an opening therein, a wire projected through the opening in the cover and through the slot in the pin, and a coiled spring under compression on, the pin between the wire and the shoulder.

HUGH MCEWAN.

and a vcoiled A 

